A number of devices for the protection of microphones of such hearing devices are known. For instance the protection coverings for the microphone openings of hearing devices are firmly integrated or glued to battery doors or face plates or modules of hearing devices. In case of dirt they have to be cleaned in an extensive and time-consuming manner.
U.S. Pat. No. 4,987,597 discloses for instance a covering plate for the protection of an opening facing to the outside of a hearing device. The covering plate is plugged from the outside over the opening to be protected of the respective device and comprises openings that are covered by sound permeable membranes. The construction disclosed requires a coupling element protruding from the respective hearing device to the outside for receiving the covering plate, for plug in the covering plate. Such a coupling element is on one hand optically disturbing and on the other hand susceptive to receive dirt due to its sharp edges. Such a covering plate furthermore shows the risk of unintentional or independent loosening and therefore may be lost or may penetrate into the ear canal of the person wearing the hearing device. Furthermore, only the opening of the hearing device showing in direction of the ear is covered, i.e. only the sound emission opening will be covered and protected. Thus, only the sound emission opening will be protected from being contaminated by dirt deriving from the ear canal, but not the microphone inlet aperture at the outside of the hearing device shell.
From DE 20208601 U1 a covering element for the sound inlet aperture is known comprising of a plastic flange with plastic gossamer stretched over the opening. Thus a protection of the microphones impermeable for cerumen is provided. Nevertheless, such a covering element only has a weak dimensional stability thereby forming crevices between the opening and the covering element accessible for dirt and humidity.
In WO 97/09864 a further device for the protection of openings directed towards the ear or ear canal is known. The respective openings are closed by a porous pin that is plugged into the canal associated to the respective opening. Such a pin may in practice disadvantageously not be removed from said opening or canal after its insertion. Thus, the pin may only be cleaned together with the hearing device, thereby remaining in its inserted position within the canal or opening. Another problem arises during the assembly of the pin, as the pin may be pushed too far or too deep into the respective canal or opening. As a result, an open chamber is provided and thus dirt may be deposited and thereby plugging the respective opening.
EP 1 439 733 further discloses a microphone protection for hearing devices with a flange in form of a ring. The flange comprises racks spanning over the opening of the flange. The flange further comprises stop elements to limit the possible insertion depth of the flange into the microphone opening of the housing of the hearing device. Thus, a damaging or displacing of the microphone by the microphone protection during the insertion process will be prevented.